As of a few hours ago my internet has slowed to a crawl.

Like literally a crawl. Did the Speedtest multiple times and got the same result, with different servers too. I tried unplugging and replugging the router but to no avail. YouTube videos buffer for a few seconds then stop. I tried ringing support but infuriatingly their call centre closes at 9pm... I have also confirmed it's not just my computer.
Is anyone else experiencing this or is it just me?